For the validation and test datasets, we used utterances from the LibriSpeech [1]} dev and test sets. The noisy utterances were generated using the same manner as the training dataset with SNR from -5 dB to 20 dB, but with noise sources that are held out from the training dataset. The test dataset consists of 2,620 utterances and the average SNR of the input signals was 7.5 dB.
